A Full-Scale Successive Alkalinity-Producing Passive System (SAPPS) for the Treatment of Acid Mine Drainage

Abstract

The successive alkalinity-producing passive system (SAPPS) located in Gangneung, South Korea was designed to treat acid mine drainage. The performance of SAPPS has been monitored intensively for 3 years at the component level (influent, settling pond A, the successive alkalinity-producing system (SAPS), settling pond B, constructed wetland, and effluent). This study evaluated the ability of SAPPS to remove acidity and iron from influents at flow rates ranging from 17 to 160 m(3)/day. The concentration of soluble Fe-total was the highest, and the pH was the lowest at low flow rates (<= 61 m(3)/day). When flow rates were over 80 m(3)/day, concentrations decreased and Fe-total was removed primarily at the SAPS stage. For flow rates of less than 61 m(3)/day, Fe-total was removed at the SAPS stage as well as in settling pond B and at the constructed wetland. Hydraulic retention times of 1 and 2 days were found to be appropriate and economical for use with the SAPS stage and for settling pond B and the constructed wetland, respectively The treatment of acid mine drainage by conventional SAPPSs is limited by the availability of alkaline materials. However, the new proposed system can address this weakness through the provisioning of a suitable alkalinity supply.